Book/Report

FZJ-2019-03705

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Schwellennahe assoziierte Strangeness-Erzeugung in der Reaktion pp $\rightarrow$ pp K$^{+}$K$^{-}$ am Experiment COSY-11

Wolke, M. (Corresponding author)FZJ*

1998
Forschungszentrum Jülich, Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/22426

Report No.: Juel-3532

Abstract: The experimental facility COSY-ll at the cooler synchrotron and storage ring COSY Jülich is focussed on studying the production of small width mesons in the proton-proton interaction close to threshold. As the valence quark system of the initial two proton state does not contain the strange quark flavour, the dynamics of such associated production mechanism is of unique interest. Hitherto, experimental cross section values of the elementary reaction conserving the baryon valence quark content, i. e. the pp $\rightarrow$ pp K$^{+}$K$^{-}$ reaction, are unknown. With high momentum transfers in. the baryon-baryon system at threshold the experimental approach probes the short range part of the nucleon-nucleon interaction. At the same time, the excitation function may reveal the strength of the $K\overline{K}$ interaction, which is of particular actuality in view of the discussions on the nature of scalar resonances in the I GeV/c$^{2}$ mass range. In preparation for first measurements the FASTBUS component within the COSY-II data acquisition system has been put into operation. Minimized system dead times of less than a millisecond result in an optimum yield from experimentally available luminosities. A first total cross section of the reaction pp $\rightarrow$ pp K$^{+}$K$^{-}$ close to threshold is obtained from a kinematically complete reconstruction of the four particle final state. Overall luminosities achieved at the internal target provide access to a cross section of 490$^{+400}_{-370}$ pb at an excess energy of 6.1 ± 1.6 MeV resultiig from the identification of two events. The normalization of measured counting rates is based on a simultaneous measurement of proton-proton elastic scattering. Event selection for both the elastic channel in view of luminosity determination and the (pp$K^{+}K^{-}$) final state arc discussed. Taking into consideration four body phase space and the proton-proton final state interaction, first estimates concerning the excitation function close to threshold may be given, baring the possibility of additional physics.

---

Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

---

Database coverage:

---